956 research outputs found
Distribution of skates and sharks in the North Sea: 112 years of change
How have North Sea skate and shark assemblages changed since the early 20th century when bottom trawling became widespread, whilst their environment became increasingly impacted by fishing, climate change, habitat degradation and other anthropogenic pressures? This article examines long-term changes in the distribution and occurrence of the elasmobranch assemblage of the southern North Sea, based on extensive historical time series (1902–2013) of fishery-independent survey data. In general, larger species (thornback ray, tope, spurdog) exhibited long-term declines, and the largest (common skate complex) became locally extirpated (as did angelshark). Smaller species increased (spotted and starry ray, lesser-spotted dogfish) as did smooth-hound, likely benefiting from greater resilience to fishing and/or climate change. This indicates a fundamental shift from historical dominance of larger, commercially valuable species to current prevalence of smaller, more productive species often of low commercial value. In recent years, however, some trends have reversed, with the (cold-water associated) starry ray now declining and thornback ray increasing. This shift may be attributed to (i) fishing, including mechanised beam trawling introduced in the 1960s–1970s, and historical target fisheries for elasmobranchs; (ii) climate change, currently favouring warm-water above cold-water species; and (iii) habitat loss, including potential degradation of coastal and outer estuarine nursery habitats. The same anthropogenic pressures, here documented to have impacted North Sea elasmobranchs over the past century, are likewise impacting shelf seas worldwide and may increase in the future; therefore, parallel changes in elasmobranch communities in other regions are to be expected
Transcriptome Analysis of Targeted Mouse Mutations Reveals the Topography of Local Changes in Gene Expression.
The unintended consequences of gene targeting in mouse models have not been thoroughly studied and a more systematic analysis is needed to understand the frequency and characteristics of off-target effects. Using RNA-seq, we evaluated targeted and neighboring gene expression in tissues from 44 homozygous mutants compared with C57BL/6N control mice. Two allele types were evaluated: 15 targeted trap mutations (TRAP); and 29 deletion alleles (DEL), usually a deletion between the translational start and the 3' UTR. Both targeting strategies insert a bacterial beta-galactosidase reporter (LacZ) and a neomycin resistance selection cassette. Evaluating transcription of genes in +/- 500 kb of flanking DNA around the targeted gene, we found up-regulated genes more frequently around DEL compared with TRAP alleles, however the frequency of alleles with local down-regulated genes flanking DEL and TRAP targets was similar. Down-regulated genes around both DEL and TRAP targets were found at a higher frequency than expected from a genome-wide survey. However, only around DEL targets were up-regulated genes found with a significantly higher frequency compared with genome-wide sampling. Transcriptome analysis confirms targeting in 97% of DEL alleles, but in only 47% of TRAP alleles probably due to non-functional splice variants, and some splicing around the gene trap. Local effects on gene expression are likely due to a number of factors including compensatory regulation, loss or disruption of intragenic regulatory elements, the exogenous promoter in the neo selection cassette, removal of insulating DNA in the DEL mutants, and local silencing due to disruption of normal chromatin organization or presence of exogenous DNA. An understanding of local position effects is important for understanding and interpreting any phenotype attributed to targeted gene mutations, or to spontaneous indels
Effect of annealing treatments on the anisotropy of a magnesium alloy sheet processed by severe rolling
The effect of annealing treatments on the normal plastic anisotropy (r-value) of a magnesium alloy, AZ61, processed by severe rolling was investigated. The various annealing treatments produce two effects on microstructure: grain coarsening and slight weakening of the texture. In addition, these treatments produce a noticeable decrease of the anisotropy that was correlated with an increase in strain rate sensitivity and a decrease of work hardening rate. It is concluded that an enhanced contribution of basal slip occurs as a consequence of the annealing treatments.The authors acknowledge the financial support from the CICYT
grant MAT 2006-02672 awarded by the Spanish Ministry of Education
and Science.Peer reviewe
Окрема думка судді в кримінальному процесі
З’ясовується
змістове
наповнення
правових
засад,
на підставі яких суддя
може
викласти
окрему
думку.
Досліджується поняття
«окремої
думки
судді» в різних
країнах та правових
системах.
Висвітлюється механізм
реалізації
окремої
думки
судді
в порівнянні з правом
зарубіжних
держав
та вносить
пропозиції
щодо
запозичення
та
ведення
аналогічних
механізмів
реалізації
окремої
думки
судді в Україні.Раскрывается
содержание
правовых
принципов,
на основании
которых
судья
может
изложить
особое
мнение.
Исследуется
понятие
«особого
мнения
судьи
» в разных
странах
и правовых
системах.
Освещается
механизм
реализации
особого
мнения
судьи
в сравнении
с правом
зарубежных
государств
и вносит
предложение
относительно
заимствования
и ведения
аналогичных
механизмов
реализации
особого
мнения
судьи
в Украине.This article investigated the legal principles on which the judge may express the separate
opinion; the existence of the notion of «the separate opinion of judge» in different countries
and legal systems is conducted. The author analyzed the mechanism of realization of the
separate opinion of judge in comparison with the law of foreign countries and made proposals
for borrowing and introduction of the similar mechanisms for realization the dissenting the
separate opinion of judge in Ukraine
Long-term Evolution of Protostellar and Protoplanetary Disks. I. Outbursts
As an initial investigation into the long-term evolution of protostellar
disks, we explore the conditions required to explain the large outbursts of
disk accretion seen in some young stellar objects. We use one-dimensional
time-dependent disk models with a phenomenological treatment of the
magnetorotational instability (MRI) and gravitational torques to follow disk
evolution over long timescales. Comparison with our previous two-dimensional
disk model calculations (Zhu et al. 2009b, Z2009b) indicates that the neglect
of radial effects and two-dimensional disk structure in the one-dimensional
case makes only modest differences in the results; this allows us to use the
simpler models to explore parameter space efficiently. We find that the mass
infall rates typically estimated for low-mass protostars generally result in
AU-scale disk accretion outbursts, as predicted by our previous analysis (Zhu
et al. 2009a,Z2009a). We also confirm quasi-steady accretion behavior for high
mass infall rates if the values of -parameter for the magnetorotational
instability is small, while at this high accretion rate convection from the
thermal instability may lead to some variations. We further constrain the
combinations of the -parameter and the MRI critical temperature, which
can reproduce observed outburst behavior. Our results suggest that dust
sublimation may be connected with full activation of the MRI. This is
consistent with the idea that small dust captures ions and electrons to
suppress the MRI. In a later paper we will explore both long-term outburst and
disk evolution with this model, allowing for infall from protostellar envelopes
with differing angular momenta.Comment: Accepted to publish in Ap
Transition Metal Dopants Essential for Producing Ferromagnetism in Metal Oxide Nanoparticles
Recent claims that ferromagnetism can be produced in nanoparticles of metal oxides without the presence of transition metal dopants have been challenged in this work by investigating 62 high quality well-characterized nanoparticle samples of both undoped and Fe doped (0-10% Fe) ZnO. The undoped ZnO nanoparticles showed zero or negligible magnetization, without any dependence on the nanoparticle size. However, chemically synthesized Zn1-xFexO nanoparticles showed clear ferromagnetism, varying systematically with Fe concentration. Furthermore, the magnetic properties of Zn1-xFexO nanoparticles showed strong dependence on the reaction media used to prepare the samples. The zeta potentials of the Zn1-xFexO nanoparticles prepared using different reaction media were significantly different, indicating strong differences in the surface structure. Electron paramagnetic resonance studies indicate that the difference in the ferromagnetic properties of Zn1-xFexO nanoparticles with different surface structures originates from differences in the fraction of the doped Fe ions that participate in ferromagnetic resonance
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Spectroscopic Characterization of Aqua [ fac-Tc(CO)3]+ Complexes at High Ionic Strength.
Understanding fundamental Tc chemistry is important to both the remediation of nuclear waste and the reprocessing of nuclear fuel; however, current knowledge of the electronic structure and spectral signatures of low-valent Tc compounds significantly lags behind the remainder of the d-block elements. In particular, identification and treatment of Tc speciation in legacy nuclear waste is challenging due to the lack of reference data especially for Tc compounds in the less common oxidation states (I-VI). In an effort to establish a spectroscopic library corresponding to the relevant conditions of extremely high ionic strength typical for the legacy nuclear waste, compounds with the general formula of [ fac-Tc(CO)3(OH2)3- n(OH) n]1- n (where n = 0-3) were examined by a range of spectroscopic techniques including 99Tc/13C NMR, IR, XPS, and XAS. In the series of monomeric aqua species, stepwise hydrolysis results in the increase of the Tc metal center electron density and corresponding progressive decrease of the Tc-C bond distances, Tc electron binding energies, and carbonyl stretching frequencies in the order [ fac-Tc(CO)3(OH2)3]+ > [ fac-Tc(CO)3(OH2)2(OH)] > [ fac-Tc(CO)3(OH2)(OH)2]-. These results correlate with established trends of the 99Tc upfield chemical shift and carbonyl 13C downfield chemical shift. The lone exception is [ fac-Tc(CO)3(OH)]4 which exhibits a comparatively low electron density at the metal center attributed to the μ3-bridging nature of the -OH ligands causing less σ-donation and no π-donation. This work also reports the first observations of these compounds by XPS and [ fac-Tc(CO)3Cl3]2- by XAS. The unique and distinguishable spectral features of the aqua [ fac-Tc(CO)3]+ complexes lay the foundation for their identification in the complex aqueous matrixes
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